During his six years in Japan, Valentine learned a lot about Japanese culture and work ethic.Getty Images/Getty Images

Peter Abraham wrote in the Boston Globe that the x-factor in determining the Red Sox interest in Darvish is Bobby Valentine, who managed six seasons in Japan and speaks Japanese. One might assume that this ability to communicate, combined with cultural understanding, would make Valentine the odds-on favorite to take Darvish under his wing.

Valentine, however, has long been concerned about the Japanese tendency to burn out pitchers at an early age. Back in 2006, he told the New York Times that "overthrowing is a definite concern."

In fairness, Valentine also said that the superior mechanics of Japanese pitchers may help them prolong their careers. “Pitchers in Japan are taught at an early age what proper form is. They’re less prone to injury than in America where they deal with results rather form.”

Jeff Hays is a teacher and writer now living in Saga, Japan. He has written extensively about the history, culture and everyday life in Japan. His treatise on Japanese baseball can be found here.

Hays totally agrees that burnout is an issue for Japanese pitchers. He points out that it is not unusual for a star pitcher to throw six innings in a Tuesday game, then come out of the bullpen in the 10th inning on Thursday to save a game, then start on Saturday and throw 167 pitches to complete an important game.

With respect to Darvish, Tom Verducci points out in Sports Illustrated that he threw 140 pitches or more in a game nine times in 2010—"More than every major league pitcher combined over the past nine years." In 2011, Darvish exceeded 140 pitches only once, but he still reached 120 pitches 15 times.

Darvish has been a real horse in Japan, pitching a lot of innings.Stephen Dunn/Getty Images

"No major league pitcher has thrown 15 120-pitch games in a season since 2005, when Livan Hernandez did so," Verducci points out.

One Japanese pitcher told Verducci,"In America, pitchers look for help when they get close to about 100 pitches. In Japan we value a complete game more."

Hays reports that the Japanese pitching philosophy is sometimes described as "Throw until you die."

He describes player drills of a generation ago, in which "players ran with massive dictionaries strapped to their backs, catchers were taught the correct way to crouch by squatting over a over a bunch of spikes, and players were motivated with slogans like 'Practice till you die' and 'Bloody urine.'"

A popular drill, only recently been abandoned by many coaches, is called the senbon-nokku ("thousand knocks"). This drill required players to catch balls until they collapsed from exhaustion. "It is still not uncommon for Japanese players to puke their guts out at the end of practice," Hays concluded.

This work ethic may be impressive, but it does not necessarily translate well to the longer MLB season, with fewer days off—especially for pitchers.

Journeyman pitcher C.J. Nitkowski debuted with the Reds in 1995, and played for seven more major league teams before he went to Japan in 2007. He pitched for the Fukuoka Softbank Hawks for two years, and he has spent the last three years pitching in Korea.

His website, cjbaseball.com, gives an excellent analysis of the technical differences between pitching in Japan and the US.

Nitkowski very astutely points out that "Japanese players really don’t have a second or third gear. It’s full throttle all the time."

"I've seen 250-pitch bullpens before, which in American eyes is absurd. Guys will practice this hard, see guys get hurt and continue to do the same routines. They know one way—work hard, work long."

Japanese players practice year round, sometimes for seven or eight hours a day. According to Hays, one American player who played in Japan said, "It is the difference between summer camp and a year in the Imperial army."

When the MLB season ends, most American pitchers go on vacation for about three months. Pitchers in Japan keep up a rigorous training program, sometimes throwing more than 200 pitches a day, more than American pitchers throw in an entire offseason week.

Japanese pitchers have often been throwing hard and often since they were 12. Hays recalled an International Herald Tribune article quoting an American pitcher in Japan: “They throw easily two or three times more pitches in their career than Americans. They play 360 days out of the year. It’s taken to an extreme that you don’t see in America.”

Having managed in Japan for six years (although he never managed Darvish), Valentine must be acutely aware of the workload Japanese pitchers impose on themselves from an early age. He has also seen the short careers of most NPB pitchers who come to America.

According to one survey, only 25 percent of Japanese pitchers are still playing at the age of 30, compared to 40 percent in the U.S. Among Japanese pitchers who played in MLB, Nomo was released at age 30, Irabu was finished at 33 and Kaz Ishii was done at 32.

Robert Whiting, an expert on Japanese baseball and the author of You Gotta Have Wa, told the New York Times, “There are subtle—and not so subtle—differences between Japanese and American baseball that make it difficult for imported pitchers to adjust.”

Tom Verducci's superb Sports Illustrated piece describes what he calls the "Third Year Wall," and presents strong evidence to support his theory that Japanese pitchers may have a couple of good years in MLB, but their performance drops off drastically starting in the third year.

Rangers assistant GM Thad Levine told Verducci, "The anecdotal assessment suggests starting pitchers have a two-year window of success followed by a rapid decline, followed thereafter by disappearance. Even a lot of the relievers have had success quickly, reaching a hot peak followed by a rapid decline."

The bottom line is that Valentine has not appeared to have pushed (at least publicly) to get the Red Sox involved in the Darvish sweepstakes.

"I have no idea if his talents will translate at the Major League level if he came here, but he's a quality pitcher. He has size, quality, velocity, breaking balls, very good hands. He makes the ball do a lot of crazy things on its way to the plate. Great competitor. If those things translate into another uniform, whether it's another uniform in Japan, who knows?"

If Valentine really wants Darvish, he's certainly taking the subdued approach. For my money, he has probably told Red Sox brass that the 25-year-old Darvish may burn out before he turns 30.